Make a major API change to BitstreamReader: split all the reading
state out of the BitstreamReader class into a BitstreamCursor class.
Doing this allows the client to have multiple cursors into the same
file, each with potentially different live block stacks and
abbreviation records.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70157 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
index 7ff4e26..ae18f2c 100644
--- a/include/llvm/Bitcode/BitstreamReader.h
+++ b/include/llvm/Bitcode/BitstreamReader.h
@@ -24,50 +24,22 @@
class Deserializer;
class BitstreamReader {
- const unsigned char *NextChar;
- const unsigned char *LastChar;
- friend class Deserializer;
-
- /// CurWord - This is the current data we have pulled from the stream but have
- /// not returned to the client.
- uint32_t CurWord;
-
- /// BitsInCurWord - This is the number of bits in CurWord that are valid. This
- /// is always from [0...31] inclusive.
- unsigned BitsInCurWord;
-
- // CurCodeSize - This is the declared size of code values used for the current
- // block, in bits.
- unsigned CurCodeSize;
-
- /// CurAbbrevs - Abbrevs installed at in this block.
- std::vector<BitCodeAbbrev*> CurAbbrevs;
-
- struct Block {
- unsigned PrevCodeSize;
- std::vector<BitCodeAbbrev*> PrevAbbrevs;
- explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
- };
-
- /// BlockScope - This tracks the codesize of parent blocks.
- SmallVector<Block, 8> BlockScope;
-
+public:
/// BlockInfo - This contains information emitted to BLOCKINFO_BLOCK blocks.
/// These describe abbreviations that all blocks of the specified ID inherit.
struct BlockInfo {
unsigned BlockID;
std::vector<BitCodeAbbrev*> Abbrevs;
};
+private:
+ /// FirstChar/LastChar - This remembers the first and last bytes of the
+ /// stream.
+ const unsigned char *FirstChar, *LastChar;
+
std::vector<BlockInfo> BlockInfoRecords;
- /// FirstChar - This remembers the first byte of the stream.
- const unsigned char *FirstChar;
public:
- BitstreamReader() {
- NextChar = FirstChar = LastChar = 0;
- CurWord = 0;
- BitsInCurWord = 0;
- CurCodeSize = 0;
+ BitstreamReader() : FirstChar(0), LastChar(0) {
}
BitstreamReader(const unsigned char *Start, const unsigned char *End) {
@@ -75,29 +47,12 @@
}
void init(const unsigned char *Start, const unsigned char *End) {
- NextChar = FirstChar = Start;
+ FirstChar = Start;
LastChar = End;
assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes");
- CurWord = 0;
- BitsInCurWord = 0;
- CurCodeSize = 2;
}
~BitstreamReader() {
- // Abbrevs could still exist if the stream was broken. If so, don't leak
- // them.
- for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
- i != e; ++i)
- CurAbbrevs[i]->dropRef();
-
- for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
- S != e; ++S) {
- std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
- for (unsigned i = 0, e = static_cast<unsigned>(Abbrevs.size());
- i != e; ++i)
- Abbrevs[i]->dropRef();
- }
-
// Free the BlockInfoRecords.
while (!BlockInfoRecords.empty()) {
BlockInfo &Info = BlockInfoRecords.back();
@@ -108,36 +63,147 @@
BlockInfoRecords.pop_back();
}
}
+
+ const unsigned char *getFirstChar() const { return FirstChar; }
+ const unsigned char *getLastChar() const { return LastChar; }
- bool AtEndOfStream() const {
- return NextChar == LastChar && BitsInCurWord == 0;
+ //===--------------------------------------------------------------------===//
+ // Block Manipulation
+ //===--------------------------------------------------------------------===//
+
+ /// getBlockInfo - If there is block info for the specified ID, return it,
+ /// otherwise return null.
+ BlockInfo *getBlockInfo(unsigned BlockID) {
+ // Common case, the most recent entry matches BlockID.
+ if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
+ return &BlockInfoRecords.back();
+
+ for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
+ i != e; ++i)
+ if (BlockInfoRecords[i].BlockID == BlockID)
+ return &BlockInfoRecords[i];
+ return 0;
}
+ BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
+ if (BlockInfo *BI = getBlockInfo(BlockID))
+ return *BI;
+
+ // Otherwise, add a new record.
+ BlockInfoRecords.push_back(BlockInfo());
+ BlockInfoRecords.back().BlockID = BlockID;
+ return BlockInfoRecords.back();
+ }
+
+};
+
+class BitstreamCursor {
+ friend class Deserializer;
+ BitstreamReader *BitStream;
+ const unsigned char *NextChar;
+
+ /// CurWord - This is the current data we have pulled from the stream but have
+ /// not returned to the client.
+ uint32_t CurWord;
+
+ /// BitsInCurWord - This is the number of bits in CurWord that are valid. This
+ /// is always from [0...31] inclusive.
+ unsigned BitsInCurWord;
+
+ // CurCodeSize - This is the declared size of code values used for the current
+ // block, in bits.
+ unsigned CurCodeSize;
+
+ /// CurAbbrevs - Abbrevs installed at in this block.
+ std::vector<BitCodeAbbrev*> CurAbbrevs;
+
+ struct Block {
+ unsigned PrevCodeSize;
+ std::vector<BitCodeAbbrev*> PrevAbbrevs;
+ explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
+ };
+
+ /// BlockScope - This tracks the codesize of parent blocks.
+ SmallVector<Block, 8> BlockScope;
+
+ BitstreamCursor(const BitstreamCursor&); // NOT YET IMPLEMENTED.
+ void operator=(const BitstreamCursor&); // NOT YET IMPLEMENTED.
+public:
+ BitstreamCursor() : BitStream(0), NextChar(0) {
+ }
+ explicit BitstreamCursor(BitstreamReader &R) : BitStream(&R) {
+ NextChar = R.getFirstChar();
+ assert(NextChar && "Bitstream not initialized yet");
+ CurWord = 0;
+ BitsInCurWord = 0;
+ CurCodeSize = 2;
+ }
+
+ void init(BitstreamReader &R) {
+ freeState();
+
+ BitStream = &R;
+ NextChar = R.getFirstChar();
+ assert(NextChar && "Bitstream not initialized yet");
+ CurWord = 0;
+ BitsInCurWord = 0;
+ CurCodeSize = 2;
+ }
+
+ ~BitstreamCursor() {
+ freeState();
+ }
+
+ void freeState() {
+ // Free all the Abbrevs.
+ for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
+ i != e; ++i)
+ CurAbbrevs[i]->dropRef();
+ CurAbbrevs.clear();
+
+ // Free all the Abbrevs in the block scope.
+ for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
+ S != e; ++S) {
+ std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
+ for (unsigned i = 0, e = static_cast<unsigned>(Abbrevs.size());
+ i != e; ++i)
+ Abbrevs[i]->dropRef();
+ }
+ BlockScope.clear();
+ }
+
+ /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
+ unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
+
+ bool AtEndOfStream() const {
+ return NextChar == BitStream->getLastChar() && BitsInCurWord == 0;
+ }
+
/// GetCurrentBitNo - Return the bit # of the bit we are reading.
uint64_t GetCurrentBitNo() const {
- return (NextChar-FirstChar)*CHAR_BIT - BitsInCurWord;
+ return (NextChar-BitStream->getFirstChar())*CHAR_BIT - BitsInCurWord;
}
-
+
+
/// JumpToBit - Reset the stream to the specified bit number.
void JumpToBit(uint64_t BitNo) {
uintptr_t ByteNo = uintptr_t(BitNo/8) & ~3;
uintptr_t WordBitNo = uintptr_t(BitNo) & 31;
- assert(ByteNo <= (uintptr_t)(LastChar-FirstChar) && "Invalid location");
-
+ assert(ByteNo <= (uintptr_t)(BitStream->getLastChar()-
+ BitStream->getFirstChar()) &&
+ "Invalid location");
+
// Move the cursor to the right word.
- NextChar = FirstChar+ByteNo;
+ NextChar = BitStream->getFirstChar()+ByteNo;
BitsInCurWord = 0;
CurWord = 0;
-
+
// Skip over any bits that are already consumed.
- if (WordBitNo) {
+ if (WordBitNo)
Read(static_cast<unsigned>(WordBitNo));
- }
}
-
- /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
- unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
-
+
+
uint32_t Read(unsigned NumBits) {
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
@@ -148,7 +214,7 @@
}
// If we run out of data, stop at the end of the stream.
- if (NextChar == LastChar) {
+ if (NextChar == BitStream->getLastChar()) {
CurWord = 0;
BitsInCurWord = 0;
return 0;
@@ -224,31 +290,10 @@
CurWord = 0;
}
-
unsigned ReadCode() {
return Read(CurCodeSize);
}
- //===--------------------------------------------------------------------===//
- // Block Manipulation
- //===--------------------------------------------------------------------===//
-
-private:
- /// getBlockInfo - If there is block info for the specified ID, return it,
- /// otherwise return null.
- BlockInfo *getBlockInfo(unsigned BlockID) {
- // Common case, the most recent entry matches BlockID.
- if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
- return &BlockInfoRecords.back();
-
- for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
- i != e; ++i)
- if (BlockInfoRecords[i].BlockID == BlockID)
- return &BlockInfoRecords[i];
- return 0;
- }
-public:
-
// Block header:
// [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
@@ -271,7 +316,7 @@
// Check that the block wasn't partially defined, and that the offset isn't
// bogus.
- if (AtEndOfStream() || NextChar+NumWords*4 > LastChar)
+ if (AtEndOfStream() || NextChar+NumWords*4 > BitStream->getLastChar())
return true;
NextChar += NumWords*4;
@@ -286,7 +331,7 @@
BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
// Add the abbrevs specific to this block to the CurAbbrevs list.
- if (BlockInfo *Info = getBlockInfo(BlockID)) {
+ if (BitstreamReader::BlockInfo *Info = BitStream->getBlockInfo(BlockID)) {
for (unsigned i = 0, e = static_cast<unsigned>(Info->Abbrevs.size());
i != e; ++i) {
CurAbbrevs.push_back(Info->Abbrevs[i]);
@@ -301,7 +346,8 @@
if (NumWordsP) *NumWordsP = NumWords;
// Validate that this block is sane.
- if (CurCodeSize == 0 || AtEndOfStream() || NextChar+NumWords*4 > LastChar)
+ if (CurCodeSize == 0 || AtEndOfStream() ||
+ NextChar+NumWords*4 > BitStream->getLastChar())
return true;
return false;
@@ -331,7 +377,7 @@
BlockScope.pop_back();
}
- //===--------------------------------------------------------------------===//
+ //===--------------------------------------------------------------------===//
// Record Processing
//===--------------------------------------------------------------------===//
@@ -407,9 +453,9 @@
// If this would read off the end of the bitcode file, just set the
// record to empty and return.
- if (NewEnd > LastChar) {
+ if (NewEnd > BitStream->getLastChar()) {
Vals.append(NumElts, 0);
- NextChar = LastChar;
+ NextChar = BitStream->getLastChar();
break;
}
@@ -462,29 +508,14 @@
}
CurAbbrevs.push_back(Abbv);
}
-
- //===--------------------------------------------------------------------===//
- // BlockInfo Block Reading
- //===--------------------------------------------------------------------===//
-
-private:
- BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
- if (BlockInfo *BI = getBlockInfo(BlockID))
- return *BI;
-
- // Otherwise, add a new record.
- BlockInfoRecords.push_back(BlockInfo());
- BlockInfoRecords.back().BlockID = BlockID;
- return BlockInfoRecords.back();
- }
-
+
public:
bool ReadBlockInfoBlock() {
if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return true;
SmallVector<uint64_t, 64> Record;
- BlockInfo *CurBlockInfo = 0;
+ BitstreamReader::BlockInfo *CurBlockInfo = 0;
// Read all the records for this module.
while (1) {
@@ -516,13 +547,13 @@
default: break; // Default behavior, ignore unknown content.
case bitc::BLOCKINFO_CODE_SETBID:
if (Record.size() < 1) return true;
- CurBlockInfo = &getOrCreateBlockInfo((unsigned)Record[0]);
+ CurBlockInfo = &BitStream->getOrCreateBlockInfo((unsigned)Record[0]);
break;
}
}
}
};
-
+
} // End llvm namespace
#endif
diff --git a/include/llvm/Bitcode/Deserialize.h b/include/llvm/Bitcode/Deserialize.h
index cc85d9f..3e90227 100644
--- a/include/llvm/Bitcode/Deserialize.h
+++ b/include/llvm/Bitcode/Deserialize.h
@@ -116,7 +116,7 @@
//===----------------------------------------------------------===//
private:
- BitstreamReader& Stream;
+ BitstreamCursor Stream;
SmallVector<uint64_t,20> Record;
unsigned RecIdx;
BumpPtrAllocator Allocator;
@@ -482,7 +482,7 @@
unsigned getRecordCode();
- BitstreamReader& getStream() { return Stream; }
+ BitstreamCursor &getStream() { return Stream; }
private:
bool AdvanceStream();
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 8079acd..fe20f72 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1346,7 +1346,8 @@
if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
return Error("Invalid bitcode wrapper header");
- Stream.init(BufPtr, BufEnd);
+ StreamFile.init(BufPtr, BufEnd);
+ Stream.init(StreamFile);
// Sniff for the signature.
if (Stream.Read(8) != 'B' ||
diff --git a/lib/Bitcode/Reader/BitcodeReader.h b/lib/Bitcode/Reader/BitcodeReader.h
index 1fbf219..0dc470b 100644
--- a/lib/Bitcode/Reader/BitcodeReader.h
+++ b/lib/Bitcode/Reader/BitcodeReader.h
@@ -86,7 +86,8 @@
class BitcodeReader : public ModuleProvider {
MemoryBuffer *Buffer;
- BitstreamReader Stream;
+ BitstreamReader StreamFile;
+ BitstreamCursor Stream;
const char *ErrorString;
diff --git a/lib/Bitcode/Reader/Deserialize.cpp b/lib/Bitcode/Reader/Deserialize.cpp
index 2014557..06da6ce 100644
--- a/lib/Bitcode/Reader/Deserialize.cpp
+++ b/lib/Bitcode/Reader/Deserialize.cpp
@@ -22,7 +22,7 @@
Deserializer::Deserializer(BitstreamReader& stream)
: Stream(stream), RecIdx(0), FreeList(NULL), AbbrevNo(0), RecordCode(0) {
- StreamStart = Stream.GetCurrentBitNo();
+ StreamStart = Stream.GetCurrentBitNo();
}
Deserializer::~Deserializer() {
diff --git a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
index 4832a4c..182404c 100644
--- a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
+++ b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
@@ -262,7 +262,7 @@
}
/// ParseBlock - Read a block, updating statistics, etc.
-static bool ParseBlock(BitstreamReader &Stream, unsigned IndentLevel) {
+static bool ParseBlock(BitstreamCursor &Stream, unsigned IndentLevel) {
std::string Indent(IndentLevel*2, ' ');
uint64_t BlockBitStart = Stream.GetCurrentBitNo();
unsigned BlockID = Stream.ReadSubBlockID();
@@ -420,8 +420,8 @@
if (SkipBitcodeWrapperHeader(BufPtr, EndBufPtr))
return Error("Invalid bitcode wrapper header");
- BitstreamReader Stream(BufPtr, EndBufPtr);
-
+ BitstreamReader StreamFile(BufPtr, EndBufPtr);
+ BitstreamCursor Stream(StreamFile);
// Read the stream signature.
char Signature[6];